Art of manufacturing square-bottom paper bags.



No. 689,499. Patented Dec. 24, I901. W. A. LORENZ.

ART 0F MANUFACTURING SQUARE BOTTOM PAPER BAGS. (Application filed. my.19, 1901.

(No Model.)

Fag. ,2. d B Fzgn. 10

mtnesses l five}: tor:

UNITED STATES PATENT OFFICE.

PAPER BAG MACHINE COMPANY,

OF PHILADELPHIA, PENNSYLVANIA,

A CORPORATION OF PENNSYLVANIA. I

ART OF MANUFACTURING SQUARE-BOTTOM PAPER BAGS.

SPECIFICATION forming part of Letters Patent No. 689,499, dated December24, 1901. Application filed March 19, 1901. Serial No. 51,818. (Nomodel.) I

To all whom it may concern:

Be it known that 1, WILLIAM A. LORENZ, a citizen of the United States,residing at Hartford, in the county of Hartford and State ofConnecticut, have invented certain new and useful Improvements in theArt of Manufacturing Square-Bottom Paper Bags, of which the following isa full, clear, and exact specification. This invention relates to theart of manufacturing square-bottom paper bags; and it has for its objectan improved method of forming the so-called diamond'fold in abellows-sided or tucked tube or blank, such r5 method being adapted foruse in connection with any well-known method of previously forming thetube or blank and of subse-.

quently pasting and folding the diamond to complete the bag.

My inve'ntiomhas more particularly for its object an improved method ofopening out the open or bottom-forming end of the blank, so as to formthe inside triangular folds in an easy and rapid manner.

My improved method includes as one of its features the engagementseparately of the upper and lower plies of the tube-and then folding thesame in opposite directions over and around adjacent folding edges, thedis tance from each of said pointsof engage- 'ment to the folding edgesbeing primarily less than the depth of the tucks; Furthermore, aftersaid plies have been folded back, so that the engagement-points havearrived in positions at opposite sides of the adjacent folding line'soredges and substantially. at right angleswith the body of the blank atsaid lines, thedistance betweensaid points of engagement is increaseduntil the tucked sides have been completely stretched out be tween them,so that finally the distance from said points to the folding-lines willbe substantially equal to the depth of the tucks.

V One of the ordinary methods of forming the diamond on a bag-blankcomprises the engage'ment of the upper and lower plies there- -of bysuitable devices generally known as tuck and box holders at suchpoints,-

of the tucks, so that as said points are separated said tucked sideswill be gradually stretched out to develop the inside triangular folds.The method of straightening out the tucked'sides is usually carried outby swingsequently the distance between such points must be increased inorder fully to stretch the tucked sides of the tube;

QFurthermore, my improved method comprises as one of its features themanipulation of the blank in the above manner, while the upper and lowerplies are preferably maintained in close proximity to each other duringthe period when the distance between the box-holders and tuck-holders isincreased 'to 'distend or stretch the tucked sides to-the requiredextent. Furthermore, I have found in practice that when theline oftravel or movement of the box and tuck holders is substantially atvrightangles with the body: of the blank while the tube plies are kept closetogether the inside triangular folds may be developed gradually and inan easy manner,

said folds maturing in the nature of a run ning fold during thedistension of the tucked sides.

My improved method is clearly'illustrated in the accompanyingdrawingsfin which similar characters denote, similar parts, and inwhich- Figure 1 is a side view of a blank, illustrating the manner inwhich the blank plies are engaged by the several instrumentalitiesemployed during the diamond-forming operathe distance of which from thebottom-defining line is substantially equal to the depth ing the deviceswhich engage one ply of the been increased, but the sides have not beenI fully distended; and Figs. 8 and'9's'howa side view and front view,respectively, of the blank 5 when the distance between the box-holdersand tuck-holders is substantially equal to the depth of the tucked side,so that thelatteris completely stretched out and the inside triangularfolds have been fully developed.

formingsection A,tl1e boundary-line between said sections beinggenerally known as the defining-line and indicated in :the' presentinstance by (1 cl.

Referring to Figs. land'2, it will be seen I that the upper'p-ly-of theblank is engaged by the so-calledbox-holders B, which, in conjunctionwith grippersb,.serveto fold theup- L per ply 12 around the edge fof amember F,

which constitutes the folding member for the upper ply of the.blank,-whilea:sim=ilar nem- 5 her F, having an edge f, forms thefolding lower ply is herein shown engaged by tuc'kholders '1, whicheooperate with pincers tand F whereby said lower ply 13 is foldedaround the edge f, the positions .of the box-hoslders and tuck-holders Band T after performingi :member for-the'lower-ply 1 3 of theztube.

theirproper-fnnction in folding the respective plies around the foldingedges f and f being clearly/shown in Fig. 4.

, .a distance from the defining-line olat equal to the-depth of'the.tncksa-nd that, furthermore, the folding edges ,7 and f are disposedbetween the points 15and said defining-line dd, 1 the position of thefolding-linerelative to the defining line remaining substantially thesame .as the plies of the tube are bent ou-tward from the position shownin Fig. ,1 to that j shown in Fig. 4, in which the plies of thetube areshown substantially at right angles with the bodyof the tube .at thefolding-lines. In .thefu-rther manipulationof the blank the'boxholdersand th ck-jholders are :movedi-n the di- 1 rection of the arrows 16 [and17, respectively,

thereby drawing the plies over their respective folding edgesfand f, andthusgradually forming the inside triangular folds after passing'theintermediate position shown in Figs.

6 and 7 to that shown in Figs. 8 and 9,when the tucked tube sides havebeen fully distended or stretched to complete the box, which may then betransformed into thediamond. (Shown in dot-and-dash lines in Figs. 8 and9.) V i I In the present case I have shown the fold- Figs. 6 and 7movement of the box-holders and tuck-holders will produce a running foldin each of the tube plies over the edges f and f, while the In thedrawings the blank 10 is shown as having tucked or bellows sides 11andcomprising the bag-section A and the bottom-- closed position. 1

Having described my invention, what I claim as new,.anddesire-tozsec-ure by Letters Patent, is-

1 Theimprovernent in the art of forminga diamond insquare-bottom paperbagsw hich comprises folding over the tube plies in opposite directionsand between such points thereof, the distance of which from the primaryfolding l-ine is less than the depthof it-he tucks.

2. The improvement in theartof forming a diamond in square-bottom paperbags'whi'ch com-prises folding over the tubepliesfin-opposite directionsand between such points thereof, the distanoeef which from the primaryfolding-line is less than thezdepthef the tucks, and increasing thedistance between .saidpoin'ts until the tube sides areicompletelydistended between them.

3. The improvement in the-artao'fforming a diamond of square-bottompaper bags which consists in the engagement-of the sides-of the Againreferring to Fig. 1, it willbe seen that the points of engagement 15 aredisposed at upperran-d lower tube plies at-points, thedistanceof whichfrom the primaryfolding-line is less than the depthef the tucks, foldingover both plies in .oppositedirectionsto positions, substantially toform right angles with the ,tube bodyat the folding-line, and subsequent-1y increasing the distance between said points to'develop theinside triangular 4. The improvement in the art of forming the diamondof square --'bettoni paper bags which comprises'the engagement oftli'esides of the upper and lower tube plies at such points-thereof,-'thedistance of which fromthe primary folding-line islessit'han the depthof the tucks, maintaining the tubeplies in closedcondition, folding over both plies inopposite directions to positionssubstantially at right angles withithe tube-body-at thefoldingline,increasing the distance between .t-hepointsof engagement to develop :theinside triangular folds, and subsequentlycompleting the diamond.

5. The improvement in the art of forming the diamond of :square-2bo-ttom paper bags which consists in engaging the plies at such pointsthereof, thed-istance of which from the defining-line is equal to thedepth of the tucks, distended between them and until the definfoldingover said plies in opposite directions ing-line and the folding-linesubstantially 00-' at and around corresponding primary foldingincide.

lines located between the points of engage- WILLIAM A. LORENZ. 5 mentand the defining-line, and subsequently Witnesses:

increasing the distance between said points CHAS. F. SCHMELZ,

of engagement until the tucked sides are fully NELLIE PHOENIX.

